Tuning the properties of injection molding polypropylene parts by in-mold annealing

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28110%2F24%3A63579920" target="_blank" >RIV/70883521:28110/24:63579920 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.aip.org/aip/acp/article/3158/1/020005/3290512/Tuning-the-properties-of-injection-molding" target="_blank" >https://pubs.aip.org/aip/acp/article/3158/1/020005/3290512/Tuning-the-properties-of-injection-molding</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1063/5.0204921" target="_blank" >10.1063/5.0204921</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Tuning the properties of injection molding polypropylene parts by in-mold annealing

Popis výsledku v původním jazyce

A way to improve sustainability of plastic products is to obtain a mono-material part, tuning the final properties by the transformation process. In the injection molding process, mold temperature cycle is recognized as a key parameter in determining the final characteristics of the part. In this work, injection molding tests coupled with in-mold annealing were conducted on an isotactic polypropylene. The polymer is injected in the cavity at high temperature (140°C and 160°C) and this temperature is kept for 5 minutes (annealing step); afterwards, the mold temperature is cooled down at room temperature. The samples are characterized by optical and electronic microscopy; furthermore, atomic force microscopy coupled with HarmoniX tool allows to characterize simultaneously the local morphology and the elastic modulus. Final morphology distribution along the sample thickness is significantly influenced by the adopted in-mold annealing conditions, in particular, an oriented zone forms close to the cavity surface, a spherulitic part in the core, and a transition zone in between. The extension of the oriented layer decreases in the presence of annealing. On its turn, morphology greatly affects mechanical properties: the oriented layer shows the highest values of elastic modulus, the transition zone shows the minimum value of elastic modulus; the elastic modulus of the spherulitic layers depends on spherulite dimensions. X-ray WAXS analyses were performed on the surface of the sample along the flow path to investigate the orientation and the crystalline phases that form during the process and to relate them with morphology.

Název v anglickém jazyce

Tuning the properties of injection molding polypropylene parts by in-mold annealing

Popis výsledku anglicky

A way to improve sustainability of plastic products is to obtain a mono-material part, tuning the final properties by the transformation process. In the injection molding process, mold temperature cycle is recognized as a key parameter in determining the final characteristics of the part. In this work, injection molding tests coupled with in-mold annealing were conducted on an isotactic polypropylene. The polymer is injected in the cavity at high temperature (140°C and 160°C) and this temperature is kept for 5 minutes (annealing step); afterwards, the mold temperature is cooled down at room temperature. The samples are characterized by optical and electronic microscopy; furthermore, atomic force microscopy coupled with HarmoniX tool allows to characterize simultaneously the local morphology and the elastic modulus. Final morphology distribution along the sample thickness is significantly influenced by the adopted in-mold annealing conditions, in particular, an oriented zone forms close to the cavity surface, a spherulitic part in the core, and a transition zone in between. The extension of the oriented layer decreases in the presence of annealing. On its turn, morphology greatly affects mechanical properties: the oriented layer shows the highest values of elastic modulus, the transition zone shows the minimum value of elastic modulus; the elastic modulus of the spherulitic layers depends on spherulite dimensions. X-ray WAXS analyses were performed on the surface of the sample along the flow path to investigate the orientation and the crystalline phases that form during the process and to relate them with morphology.

Druh

D - Stať ve sborníku

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Proceedings of the 38th International Conference of the Polymer Processing Society (PPS-38)

ISBN

978-0-7354-4917-6

ISSN

0094-243X

e-ISSN

—

Počet stran výsledku

7

Strana od-do

—

Název nakladatele

American Institute of Physics

Místo vydání

Meville

Místo konání akce

St Gallen

Datum konání akce

22. 5. 2023

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

001223668700050